In the food industry, products of any shape and size and in any position are conveyed and weighed. The products are weighed either dynamically or statically. In static weighing, the transport system is stopped, and the product is weighed before it is transported onward (start/stop system). In dynamic weighing, the products are weighed while being transported. Multilane systems that use several weighing cells arranged side by side achieve a particularly high throughput.
In contemporary industrial production, the weighing system used must be suitable for high product throughputs and for any product formats (that is, products of any size and shape and/or in any spatial orientation), in order to avoid retrofitting to the extent possible. If several weighing cells are arranged side by side in a multilane weighing system, the case can occur, for example, that a product loads three weighing cells, while an adjacent second product simultaneously also loads one or more of these weighing cells, that is to say the products “share” weighing cells. Although the total weight of the two products can be acquired as a sum of the partial weights of all the loaded weighing cells, the individual weight is nevertheless not determinable. This problem could be avoided by adjusting the weighing cell number taking into consideration the product size and the product position. However, in the case of alternating product sizes, this adjustment is time consuming and cost intensive. A rapid acquisition of the individual weights of adjacently or sequentially transported products is not possible in this manner. Frequently, the products to be weighed also have to be positioned relatively accurately for the weight acquisition, so that, for example, minimum spacings between the products, both in the conveyance direction and also transversely thereto, must be complied with.
From DE 10 2005 055 755 A1, a method for weighing with several weighing cells is known, in which several weighing cells are arranged side by side and in which the weight of a product to be weighed can be distributed over several of these weighing cells. By coupling the respective weighing signals, the weight of this product can then be calculated from the partial weights acquired.
U.S. Pat. No. 3,643,798 describes a weighing and sorting device for letters, in which, as needed, rolls can be moved in the vertical direction so that supporting rods protruding between them can temporarily receive a letter previously lying on the rolls. The supporting rods are coupled with a weighing cell, in order to acquire the weight of the letter. However, this device as well does not make it possible to promptly acquire the individual weights of multiple products provided side by side or one after the other.